Lec 3 Flashcards
What is the prophyrins?
Cyclic compound consist of 4 pyrrole ring connection by methine bridges
What is the difference between porphyrins compounds?
Side chane and distribution of it
What is heme ?
Protoporphyrin IX (one of porphyrine compounds) with FE
Where biosynthesis of heme occurs ?
In liver (15%) & in erythrocytes (85%)
What is the enzyme that shared in first step of heme biosynthesis?
Aminolevulinic acid synthase 1
What is the precursor of aminolavulinic acid ?
Glycine & succinyl coA
What is the products of first step of heme biosynthesis?
Aminolevulinic acid & coA & co2
What is the rate limiting step in heme biosynthesis?
Aminolevulinic acid synthase
Does heme affect ALAS1?
Yes inhibit it
What is the enzyme that lead inhibit it in heme biosynthesis?
Aminolevulinic acid reductase & ferrochelatase
What is the porphyria type I
Deficiency in utoporphyrinogen III synthase
What is the enzyme that convert protoporphyrin IX to heme ?
Ferrochelatase enzyme which add FE to protoporphyrin
Ferrochelatase enzyme found in ?
Mitochondria
Aminolevulinic acid synthase found in ?
Moitochondia
How I can detected the deficiency of FE?
By elevated the zinc protoporphyrin which zinc bind to protoporphyrin instead of FE
What is the porphyria?
Porphyria refers to a group of disorders that result from a buildup of natural chemicals that
produce porphyrin in the body.
What is the categories of porphyria?
Acute (affect CNS) cautaneous (affect the skin)
Which one of porphyria is recessive ?
Congenital eythropoietic porphyria
What is the result of prophyria?
Formation of superoxide radical , skin blister, skin darken
What is the most common porphyria ?
Porphyria cutanea tarda
What is the cause of porphyria cutanea tarda ?
Deficiency in uroporphyrinogin decarboxylase enzyme
What is the function of uroporphyrinogen decarboxylase?
Convert uroporphyrin to coproporphyrinogen
What is the result of porphyria cutanea tarda?
Acummulation of uroporphyrogen in urine which lead to converted the color of urine to red , and lead to red to brown skin eruptions
What is the significant of heme degradation ?
Prevent heme toxicity
Excretory system
Product of degradation act as messenger products
Response to oxidative stress
What is the enzyme that act on first step of heme degradation?
Heme oxygenation
The first step of heme degradation need NADPH or NADH or FADH2?
NADPH
What is the compound that result from first step of heme degradation?
Biliverdin & co & FE+3
What is the enzyme that convert biliverdin to bilirubin?
Biliverdin reductase (need NADPH)
Synthesis of bilirubin occurs where?
In macrophages
What is the protein that bilirubin bind with it in blood
Albumins
What is the conjugation form of bilirubin?
Bilirubin diglucuronide
Which enzyme convert bilirubin to bilirubin diglucuronide
Bilirubin glucuronyl transferase (needed 2 glucornic acid)
What is the color of bilirubin?
Red-orange
What is the effect of salicylate & sulfonamide on bilirubin?
It replaces it in bilirubin which lead to enter CNS and neural damaged
Deficiency in bilirubin glucurnyl transferase lead to ?
Gilbert syndrome & crigler najjar
Deficiency in enzyme that transport conjugated bilirubin out the liver lead to
Dubin-Johnson syndrome
How urobilinogen synthase ?
Bacteria reduced bilirubin diglucuronide by remove glucornic acid
What is the compound that secreted to feces (final compound of bilirubin) and what is the color of it and how it production?
This compound is sterocobilin and produce by oxidized urobilinogen and have brown color
Urobilinogen or sterocobilin secreted by urine and which one by feces?
Urobilinogen by iron & sterocobilin by feces
What is the juandice ?
Yellow color of skin , nail bad & sclera
He have 3 type of juandice, mention them and what is the type of bilirubin increase during this ?
1-prehepatic juandice, which lead to increase in unconjugated bilirubin
2-hepatocellural juandice, which lead to increased in both conjugated & unconjugated bilirubin
3-posthepatic or cholestatic juandice, which lead to increase in conjugated bilirubin
What is the kernicterus?
Damaged to brain due to accumulation of bilirubin in brain
By any type of bilirubin kernicterus can occurs ?
By unconjugated because it is water insoluble so it can bass B.B.B